build: remove unused reactifex packages

Remove reactifex and @edx/reactifex packages from devDependencies as they are no longer
needed. Translation extraction functionality has been verified to work
correctly without these dependencies.

Co-Authored-By: Claude <[email protected]>

Author: feanil

package-lock.json

@@ -69,12 +69,10 @@
     "@commitlint/cli": "19.8.1",
     "@commitlint/config-angular": "19.8.1",
     "@edx/browserslist-config": "^1.1.1",
-    "@edx/reactifex": "2.2.0",
     "@openedx/frontend-build": "^14.6.2",
     "@testing-library/jest-dom": "6.8.0",
     "@testing-library/react": "14.3.1",
     "glob": "11.0.3",
-    "reactifex": "1.1.1",
     "redux-mock-store": "1.5.5"
   }
 }